Question

What happens when kerosene spills in a puddle of water?

Answer 1

After you spill the kerosene to the water, you then must expend more energy and effort to separate them before you can use either the water or the kerosene. It floats on the surface of water because density of kerosene is lower than the water.
You will get a layer of kerosene and a layer of denser water under it. The two do not mix well